Metal testing machine



Nov. 11, 1941. J w ALEXANDER 2,262,084

METAL TESTING MACHINE Filed Dec. 12, 1940 5 Sheets-Sheet 1 Fig.1

Nov. 11, 1941. J. w. ALEXANDER METAL TESTING MACHINE Filed Dec. 12, 19405 Sheets-Sheet 2 Nov. 11,1941 J. w. ALEXANDER METAL TESTING MACHINEFiled Dec. 12, 1940 3 Sheets-Sheet; 3

Fig.4

Patented Nov. 11, 1941 UNITED sr TESPATE QFFICE Application December 12,1940, Serial No. 369,901 In Great Britain November 28, 1939 2 Claims.

This invention relates to metal testing machines of the kind in which aspecimen sheet is forced into or through a die by a punch.

The object of the present invention is to provide a simple andconvenient means whereby a graphic record can be made of both thepressure exerted on the specimen and the relative axial movement of thepunch and die.

The invention comprises the combination of a torsionally resilientrotary driving means for eifecting the relative movement between thepunch and die, a style and operating mechanism therefor carried on andoperable by the said means, and a stationary chart holder mounted oradapted to be mounted adjacent to the style.

In the accompanying sheets of explanatory drawings:

Figure 1 is a sectional front elevation and Figure 2 a plan of a metaltesting machine embodying the invention, Figure 1 being a section on theline l-l of Figure 2.

Figure 3 is a section on the line 33 of Figure 1.

Figure 4 is a fragmentary side view of the style and driving meanslooking from the right of Figure 1.

In carrying the invention into effect as shown, I employ a testingmachine comprising a hollow body part a having mounted in its open upperend a stationary tool in the form of a die I) through which can pass amovable toolin the form of a punch c on the upper end of a verticalplunger d. The upper portion of the plunger d is screw threaded andengages a complementary screw thread in an axially movable butnon-rotatable nut or sleeve e having at its upper end an annular support1 for the flat sheet metal specimen 9 to be tested, the punch beingarranged to pass through the specimen support. The sleeve e extendsthrough and is in screw thread engagement with a worm wheel h which isheld against axial movement on a shoulder or bush 2' in the body part aby a stationary retaining ring 7' surrounding the sleeve, this ringbeing provided with a key k which by engagement with a longitudinalgroove m in the sleeve serves to prevent rotational movement of thelatter. The worm wheel 72. is in engagement with a worm n on the innerend of a spindle 0 which extends through the front of the body part a,and which is provided at its outer end with an operating hand wheel 12.For determining the relative positions of the plunger d and sleeve epreparatory to a testing operation being performed on the specimen g, acatch member q in the form of an axially slidable horizontal rod ismounted on and extends through one side of the body part a, this catchmember being loaded by a spring 1 which tends to move it into anoperative position in which its inner end can pass through a hole s inthe sleeve into a blind hole in the plunger and thereby hold the latterand the sleeve stationary. At its outer end the catch member q isprovided with a finger piece or knob 11. whereby it can be moved againstthe action of its loading spring 1- into an inoperative position clearof the plunger d and sleeve e. Normally the catch member 11 is held inits inoperative position by the engagement of a projection 12 on thecatch member with a recess '11; at the outer end of a slot :r in a fixedguide :1 through which the catch member extends. To bring the sleeve eand plunger cl into the positions in which they can be held by the catchmember q, the hand wheel p is first actuated for imparting to the sleevethe axial movement required to bring the hole 8 in the sleeve into aposition in which it can be engaged by the catch member. The plunger dis then rotated in the manner hereinafter described until the blind hole8 in the plunger is engaged by the inner end of the catch member q. Theplunger d and sleeve e now occupy positions in which the upper end ofthe punch a on the plunger and the upper side of the specimen support 1on the sleeve lie flush with each other and adjacent to the underside ofthe die 17. If it is now required to perform a testing operation on thespecimen g, the catch member (1 is moved to its inoperative positionclear of the plunger (1 and sleeve e, and the hand wheel 11 is againactuated for moving the sleeve axially into a position in which thespecimen is clamped between its support and the underside of the die b,this movement of the sleeve being accompanied by similar movement of theplunger due to the screw thread connection between these parts. Theplunger 01 is then rotated relatively to the sleeve e and is therebycaused to move the punch c axially for forcing the specimen g throughthe dieb, the extent of the relative movement that occurs between thepunch c and die b before the specimen is fractured serving as a measureof the ductility of the specimen.

For enabling the required rotary movement to be imparted to the plunger(1, the lower end of the latter is slidable through and splined to arotatable sleeve 2 (hereinafter termed the driven member) which issupported by ball bearings 3 in the lower portion of the body part a.Coaxially with and adjacent to the driven member 2 there is freelymounted in the body part a a rotatable member 4 (hereinafter termed thedriving member) which in the example shown has the form of an annularworm Wheel, and which is engaged by a worm 5 on the inner end of aspindle 6 extending through the front of the body part, the outer end ofthis spindle being provided with a hand wheel 1 whereby the drivingmember can be rotated. Alternatively the driving member may be adaptedto be rotated by power. The underside of the driving member 4 isprovided with a pair of projections 9 whereby rotational movement can betransmitted from the driving member to the driven member 2 through anyconvenient springs as Ill of sufficient strength to enable the requiredturning effort to be imparted to the plunger d. In the example shown thesprings are contained in, and carried by slidable rods extendingthrough, housings l2 at the outer ends of a pair of radial arms |3 onthe driven member 2, the rods being adapted at one end to be acted on bythe projections 9 on the driving member 4, and being provided withcollars l4 adapted to act on the springs. On one of the radial arms |3of the driven member 2 there is pivoted at IS a lever having a long arml6 and a short arm IT. The latter arm of the lever is adapted at itsouter end to be acted on by the adjacent projection 9 on the drivingmember 4, so that relative angular movements of the driving and drivenmembers 4, 2 cause the lever to be moved about its pivot axis under thecontrol of any convenient loading spring I8 to move the lever l6, l1into a position in which the long arm l6 abuts against an adjustablestop |9 on the lever supporting arm |3. On the outer end of the longlever arm H is mounted any convenient style 20, such as a pen or pencil,for drawing a line on a chart (not shown) carried by a table or holder2|. Preferably and as shown the part of the lever arm l6 which carriesthe style 20 is made separately from and connected by a horizontal pivotpin 22 to the other part of that arm, so that the style can rest on thechart.

The table or holder 2| is supported at a position beneath and adjacentto the style 29 on the upper end of a vertically adjustable carrier 23,the latter being mounted in any convenient stationary support 24. At oneside the carrier 23 is provided with a vertical toothed rack 25 which isengaged by a pinion 26 on the inner end of a spindle 26" extendingthrough the front of the support 24, the outer end of this spindle beingprovided with a hand wheel 21 whereby the spindle can be rotated foreffecting vertical adjustment of the carrier through the interaction ofthe rack and pinion. Depending from the underside of the table or holder2|, is a cylindrical member 28 which is accommodated in a correspondingaperture 29 in the carrier 23, and which permits the table or holder tobe adjusted about a vertical axis. For adjustably securing the table orholder 2| to the carrier 23 any convenient clamping means are employed.Such means in the example shown are carried by the support 24 andcomprise a pair of clamping members 30, 3| arranged end to end andshaped at one side to embrace a part of the cylindrical member 28depending from the table or holder 2 The clamping member 30 is formed orprovided on the inner end of a spindle 33 which passes through a bore inthe other clamping member 3| and extendsfrom the front of the support24. The outer end of the spindle 33 is screw threaded and carries a nut34 provided with an operating hand lever 35, the nut being adapted toact on the adjacent end of the clamping member 3|. By appropriatemanipulation of the operating lever 35 the clamping member 30, 3| can becaused to grip or release the member 28 depending from the table orholder 2|.

In the example shown the body part a is car- This spring tends ried onthe support 24 by short vertical members 36 which serve to interconnectthe body part and support.

When the machine above described is in use, the style 20 draws on thechart a line which serves to record the main features of the test.Relative angular movement of the driving and driven members 4, 2 underthe action of the force applied to the spindle 6 causes the line drawnby the style 20 to move away from a given datum circle on the chart andso gives a measure of that force. When the specimen 9 fractures theforce required to move the plunger (1 falls and the line consequentlyreturns more or less suddenly towards the datum circle. From the shapeof the line, the yield point of the specimen 9 can be ascertained, andthe length of the line up to the point indicating fracture serves as ameasure of ductility.

If desired a graduated disc 31 may be employed for indicating the extentof the angular movement imparted to the spindle 6 by the force to bemeasured. The spindle B is arranged to pass through a central hole inthe disc 31 which is mounted on the front of the body part a so as to becapable of angular adjustment relatively to an index mark on the spindleor a part carried by the spindle.

The invention is not limited to the example above described assubordinate mechanical or constructional details may be varied. 7

By this invention the required record of the testis obtainable in a verysimple and convenient manner.

Having thus described my invention what I claim as new and desire tosecure by Letters Patent is:

1. A metal testing machine comprising the combination of a punch, astationary die into or through which a metal specimen can be forced bythe punch, a rotatable and axially movable plunger carrying the punch, anon-rotatable sleeve carrying the plunger, the sleeve having a screwthread connection with the plunger so that rotation of the latter isaccompanied by axial movement thereof, torsionally resilient drivingmeans consisting in part of rotatable but axially immovable driving anddriven members and in part of spring means for transmitting movementfrom the driving member to the driven member, the plunger having aslidable connection with the driven member so that the plunger isrotatable by but capable of axial movement relatively to the drivenmember, a style, a lever carrying the style, the lever being mounted onone of the said members, means on the other of the said members foroperating the lever in response to relative movement between the saidmember, and a stationary chart holder which is situated adjacent to thestyle and over which the style is movable for recording on a chartcarried by the holder the motion of the driving means and the relativemovement between the driving and driven members.

2. A metal testing machine as claimed in claim 1 and having incombination a hollow body part in which the die, the sleeve carrying theplunger, and the torsionally resilient driving means are mounted, astationary support carrying the body part and the chart holder, meansfor adjusting the position of the chart holder, and clamping means forsecuring the chart holder in the desired position.

JAMES WOLFE ALEXANDER.

